No health-based violations on EPA record since 2016.
Serves about 8,265 people (2,755 connections) with groundwater bought from City of Round Rock and Manville WSC.
From EPA's record for TX2460152. PurityMap is independent of Williamson County WSID 3.
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No health-based violations in the last 10 years, from EPA's SDWIS compliance database.
EPA required this system to test for 30 unregulated and emerging contaminants, from February 2025 to August 2025.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| Lithium | 71.8 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Above the referenced health-based guidance value | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorononanoic acid (PFNA) | 5 ng/L | 10 ng/L federal MCL (2024) | Within a historical reference; current applicability unverified | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorobutanesulfonic acid (PFBS) | 3.5 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Within the referenced health-based guidance value | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoropentanoic acid (PFPeA) | 3.1 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-17 to 2025-08-18 | UCMR5 Analytical Results: WILLIAMSON COUNTY WSID 3 (TX2460152) |
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
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Screening: quick check, not lab-grade
Safe Home (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
Turnaround: 5 minutes
What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638 · 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Get PurityMap updates about this water system.
Follow this water →Williamson County WSID 3's phone number on EPA record is 512-432-2300. Its mailing address is 100 CONGRESS AVE STE 1300, AUSTIN, TX 78701-2744.
According to EPA's record, Williamson County WSID 3 uses groundwater bought from City of Round Rock and Manville WSC.
No health-based violations on EPA record since 2016. EPA also lists 9 missed or late tests or reports in 10 years. The record comes from EPA's SDWIS compliance database.
The 90th-percentile lead result in Williamson County WSID 3's latest lead and copper round, which ended in December 2023, was 0.498 µg/L, below the federal action level of 15 µg/L.
PurityMap has no verified website for Williamson County WSID 3. Its phone number on EPA record is 512-432-2300. Its mailing address on EPA record is 100 CONGRESS AVE STE 1300, AUSTIN, TX 78701-2744. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.